Grinding-machine.



B. SACHS.

GRINDING MACHINE.

APPLICATION 11,121) MAY 1a, 1908.

Patented Apr. 20, 1909.

UNITED sTATEs PAT NT OFFICE. I

ERNST SACHS, SCHWEINFURT, GERMANY:

' GRINDING-MACHINE.

Specification of Letters Patent.

. Patented April 20, 1909.

Application filed Kay .13, 1908. Serial No. 482,708.

or ball bearings, the machine being of the kind described in my application for patent, Serial Number 416,313, of which it is a modification.

The essential oint of the invention is that the device whic hcarries the work is iven the oscillating movement which ro uces the cross sectlon of the groove in t e shape of an arc of .a circle, and is adjusted in accordance with the radius ofcurvature, while the grinding wheel, apart from its rotation,

' receives only a movement of advance in accordance with the progress of the work and its wear. The object of this arragement is to eflect the adjustment by the work holder only, which has the advantage that, when a number of articles of the same dimensions are manufactured, the position of the work holder once adjusted, need notbe altered, for the distance of the, race groove from the axis of oscillation always remains the same, and the wear and the advance of the grinding wheel do. not affect the accuracy of the work. Compared to devices with an oscillating grinding wheel, this arrangement has the advantage that an unskilled workman can grind the grooves with the accuracy required for ball earings. Owing to the possibilit of securely supporting it, a grindmg whee of a large diameter can be used, whereb the output of the machine isconsiderab y increased. As the workv holder can remain in its adjusted position even when the work is being replaced in it, all the causes liable to bring about variations in the dimensions of the articles manufactured are done away with, and more accurate work is done ina shorter time without any special attention being required.

In the -accompanyin drawing which forms apart of this spec cation, a construc' tion according to this invention 1s illustrated byway of example.

Figure 1 is a vertical longitudinal section, and Fig. 2 a lan of the grinding machine.

' On the maciiine frame or standard justable' in suitable rismatic gui es, b means of a screw s in le f and crank hand e 'e, a slide s on w ich a transverse slide 6 guided in the same manner, can be advanced or withdrawn by the handle 0 through the intermediary of a worm gear and ,tooth rack or any other convenient gear in the well known manner, namely transversely of the axis of the grinding wheel a mounted on the bracket 6, while the slide 8 enables the whole device to be moved in the longitudinal direc-.

tion. On-the s indle of the grinding wheel a is mounted a riving pulley which is connected by a belt to a counters aft, as shown in Fig. 1 by dotted lines.

The work (1 is fixed in an desired manner opposite the grinding whee for instance by means of a mandrel which is rotatably arranged between fixed points and is driven from abelt or cord ulley g rotatabl mounted on one of the sai points, the sai mandrel being connected to it by suitable clutch de-- vices which can be easily thrown out of gear. The cord ulley g is driven from the countershaft. T e bracket h supporting the device for fixing the work, is mounted'on a conical is ad.

pin 71 in suitable guides, so that it can be adjusted at right angles to the axis of the grinding wheel by means of a screw s indle A hand wheel 1 on a displaceable olt permits of the adjustment of the mandrel carrying the work, in the direction of its axis, in order lace the central plane of the groove cointo ci ent with the axis of oscillation. The

movement of the bracket it toward the grinding'wheel gives the adjustment in accordance .with the radius, for the circumference ofthe i ht in the correspondingly s aped recess, 1-

we wh' e it can easily rotate about its axis without jammin The special arrangement in the machine body or frame gives the oscillating device a uide free from vibrations, which has a favora le effect on the accuracy-of the the work holder, can be efiected in any suitable manner, for instance by hand, or by a mechanical gear. The latter is constituted in the construction illustrated by a crank disk t connected to the bracket h by means of a rod m, the said crank being rotated by the countershaft with the assistance of a belt pulley 0 and of a bevel wheel gear n. It is preferable to use a clutch which would enable the said driving ear to be disconnected, in

order to enable t e oscillating device to be stopped at times, for instance when re lacing the work. The crank pin with which therod m is engaged is adjustable on the disk It in the radial direction in order that the work holder could swing accordingl to the requirements, to a greater or sma er angle. The grinding wheel a is preferably provided with a protecting hood, not shown in'the drawing, w ich, when cooling is necessary, is provided with sup ly pipes for furnishing a jet of wator for the work. The machine frame p is then provided with a' collecting trough from which the rinsing water is again discharged in the usual manner.

The workin of the machine is as follows. After the Wor d which is already rovided with a circumferential groove, but as to be ground or finished to the exact measurements, has been secured to a mandrel, the latter is inserted between the points of the bracket 72., the clutch device connectin it simultaneously to the pulley g. By suita 1y adjusting the work carrier in the longitudinal and transverse directions b means of the res ective adjusting devices and 7c, the work is rought into such position that it is exactly opposite the grinding wheel, and its circumference is at that distance from the axis of oscillation of the pin a which is equal to the desired radius, that is to say, the cross section of the groove is made in the sha e of the desired arc of a circle, as soon as t e given depth of grindin and, therefore, the required diameter 0 the ring has been reached or obtained. This is easily ascertained b measurin it by means of a gage; The grin ing whee a is first adjuste by means of the longitudinally displaceable Sllde s in such manner that the axis of the pin 71 comes to lie .in its central plane, whereu on, by shifting the transversely movable side b it is advanced to such an extent that its circumference touches the work, and, during the working of the machine it grinds the in the work which is rotating and simultaneousl swingingto and fro. If necessary, a sma further advance-is made in accordance with the depth of the treatment, or the groove wear of the grinding wheel. After the work has been completed, and the driving devices forhthe work and the oscillating appliance stopped, the transverse su port b is withdrawn, whereu on the worii is released from the brac at h, and another piece of the same dimensions can be placed on the mandrel. After the latter has been inserted, there is no need to make another adjustment, but after the advance of .the

grinding wheel, and after throwing into gear the device, the work can begin at once, as all the parts are at their correct relative positions. As the extent of the treatment is given by the position of the work holder which remains without any change, and the advance of the grinding wheel does not require any specia attention, the attendance on the machine, after the first adjustment, is limited merely to replacing the work, throwing the driving mechanism in-and out of gear and to bringing the grinding wheel in contact so that one man can attend to several such machines. Nevertheless, owing to the automatic working of the machine, ver accurate work is obtained as regards un' ormity of the articles treated.

What I claim as my invention, and desire to secure by Letters Patent, is

1. In a grindin machine for forming race grooves 0 ball earings, the combination with a rotating grinding wheel, of a pivotally supported rotating work carrier, the axis of sai pivot extending in a plane perpendicular to and between the axes of said wheel and carrier, and mechanically actuated means for oscillating the work carrier.

2. In a rinding machine for forming race grooves of ball bearin s, the combination with a rotating grinding w eel, of a ivotally supported rotating work carrier plhced in front of the grinding wheel, the axes of said wheel and carrier being arranged in parallel planes, and mechanically actuated means for oscillating the work carrier.

3. In a grindin machine for forming race grooves of ball earings, the combination with a pivotally supported rotating work carrier, of a rotatin grinding wheel havin itsaxis parallel with the axis of said whee and adjustable in front of the Work and mechanically actuated means for oscillating the work carrier.

4. In a grindin machine for forming race grooves 0 ball bearings, the combination with a rotatable work carrier pivotally su ported, the axis of rotation being at right angles to the axis of oscillation, of a rotating grinding wheel arranged with its axis parallel with the axis of the work carrier, the axis of said pivot extending in a lane intermediate the axes of said wheel and carrier and means for oscillating the work carrier.

5. a 1grinding machine for forming race grooves 0 ball earings, the combination grooves 0 with a rotating grinding wheel, of a rotating work carrier having its axis arallel with and in rear of the axis of said w eel, a pivot supporting the work carrier, and means for oscillating the said work carrier, the axis of said pivot extending in a plane intermediate the axes of said wheel and carrier. 6. In a rinding machine for forming race 5 ball bearings, the combination with a machine frame-or standard havin a socket and a pivot seated therein and capa 1c of oscillating on its seat, of a rotatable work carrier mounted upon and supported by the pivot and being adjustable with respect to the axis of oscillation of the said pivot, a rotating grindin wheel adjustably arranged with respect to the axis of oscillation in front of the work carrier, and means for oscillating the pivot.

7. In a grinding machine for forming race grooves of ball bearings, the combination with a conical pivot capable of oscillating in a conical seat, of a rotatable work carrier supported by the said pivot, a rotatable grinding wheel, and means for oscillating the pivot and the work carrier.

8. In a grindin machine for forming race grooves of ball earings, the combination with a conical pivot, of a corresponding conical seat in the standard of the machine, the

said pivot being ca able of oscillating in its seat and maintaine therein by its weight, a rotatable work carrier supported by the said )ivot, a rotatable grinding wheel, and means ior oscillating the ivot and the work carrier.

In testimony w ereof I have set my signature to this specification in the presence of two subscribing witnesses.

ERNST SACHS. Witnesses:

FRANZ STROHMER, ROBERT W. IIEINGARTNER. 

